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authorRafael J. Wysocki <rjw@sisk.pl>2010-01-28 01:47:38 +0300
committerRafael J. Wysocki <rjw@sisk.pl>2010-02-26 22:39:11 +0300
commitf8824cee405c62ba465b85365201166d9cf86a14 (patch)
tree90020be3264ff98bad2f14759127a2d9693673d8
parent97df8c12995c5bac73e3bfeea4c5be155c1f4401 (diff)
downloadlinux-f8824cee405c62ba465b85365201166d9cf86a14.tar.xz
PM: Allow device drivers to use dpm_wait()
There are some dependencies between devices (in particular, between EHCI USB controllers and their OHCI/UHCI siblings) which are not reflected by the structure of the device tree. With synchronous suspend and resume these dependencies are taken into accout automatically, because the devices in question are always registered in the right order, but to meet these constraints with asynchronous suspend and resume the drivers of these devices will need to use dpm_wait() in their suspend/resume routines, so introduce a helper function allowing them to do that. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
-rw-r--r--drivers/base/power/main.c11
-rw-r--r--include/linux/pm.h2
2 files changed, 13 insertions, 0 deletions
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 6efef9fb23a1..0e26a6f6fd48 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -1046,3 +1046,14 @@ void __suspend_report_result(const char *function, void *fn, int ret)
printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
}
EXPORT_SYMBOL_GPL(__suspend_report_result);
+
+/**
+ * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
+ * @dev: Device to wait for.
+ * @subordinate: Device that needs to wait for @dev.
+ */
+void device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
+{
+ dpm_wait(dev, subordinate->power.async_suspend);
+}
+EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
diff --git a/include/linux/pm.h b/include/linux/pm.h
index 9c16cd20fc96..e80df06ad22a 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -512,6 +512,7 @@ extern void __suspend_report_result(const char *function, void *fn, int ret);
__suspend_report_result(__func__, fn, ret); \
} while (0)
+extern void device_pm_wait_for_dev(struct device *sub, struct device *dev);
#else /* !CONFIG_PM_SLEEP */
#define device_pm_lock() do {} while (0)
@@ -524,6 +525,7 @@ static inline int dpm_suspend_start(pm_message_t state)
#define suspend_report_result(fn, ret) do {} while (0)
+static inline void device_pm_wait_for_dev(struct device *a, struct device *b) {}
#endif /* !CONFIG_PM_SLEEP */
/* How to reorder dpm_list after device_move() */